Add a new NetworkTimeHelper impl (bd64b8d5) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/location/gnss/NetworkTimeHelper.java

+19 −2

Original line number	Diff line number	Diff line
		@@ -31,6 +31,14 @@ import java.io.PrintWriter;
		*/
		abstract class NetworkTimeHelper {

		/**
		* This compile-time value can be changed to switch between new and old ways to obtain network
		* time for GNSS. If you have to turn this from {@code true} to {@code false} then please create
		* a platform bug. This switch will be removed in a future release. If there are problems with
		* the new impl we'd like to hear about them.
		*/
		static final boolean USE_TIME_DETECTOR_IMPL = false;

		/**
		* The callback interface used by {@link NetworkTimeHelper} to report the time to {@link
		* GnssLocationProvider}. The callback can happen at any time using the thread associated with
		@@ -47,8 +55,14 @@ abstract class NetworkTimeHelper {
		static NetworkTimeHelper create(
		@NonNull Context context, @NonNull Looper looper,
		@NonNull InjectTimeCallback injectTimeCallback) {
		if (USE_TIME_DETECTOR_IMPL) {
		TimeDetectorNetworkTimeHelper.Environment environment =
		new TimeDetectorNetworkTimeHelper.EnvironmentImpl(looper);
		return new TimeDetectorNetworkTimeHelper(environment, injectTimeCallback);
		} else {
		return new NtpNetworkTimeHelper(context, looper, injectTimeCallback);
		}
		}

		/**
		* Sets the "on demand time injection" mode.
		@@ -74,7 +88,9 @@ abstract class NetworkTimeHelper {
		* Notifies that network connectivity has been established.
		*
		* <p>Called by {@link GnssLocationProvider} when the device establishes a data network
		* connection.
		* connection. This call should be removed eventually because it should be handled by the {@link
		* NetworkTimeHelper} implementation itself, but has been retained for compatibility while
		* switching implementations.
		*/
		abstract void onNetworkAvailable();

		@@ -82,4 +98,5 @@ abstract class NetworkTimeHelper {
		* Dumps internal state during bugreports useful for debugging.
		*/
		abstract void dump(@NonNull PrintWriter pw);

		}

services/core/java/com/android/server/location/gnss/TimeDetectorNetworkTimeHelper.java

0 → 100644

+339 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2022 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.server.location.gnss;

		import android.annotation.DurationMillisLong;
		import android.annotation.ElapsedRealtimeLong;
		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.app.time.UnixEpochTime;
		import android.os.Handler;
		import android.os.Looper;
		import android.os.SystemClock;
		import android.util.IndentingPrintWriter;
		import android.util.LocalLog;
		import android.util.Log;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.server.LocalServices;
		import com.android.server.timedetector.NetworkTimeSuggestion;
		import com.android.server.timedetector.TimeDetectorInternal;
		import com.android.server.timezonedetector.StateChangeListener;

		import java.io.PrintWriter;
		import java.util.Objects;

		/**
		* Handles injecting network time to GNSS by using information from the platform time detector.
		*/
		public class TimeDetectorNetworkTimeHelper extends NetworkTimeHelper {

		/** Returns {@code true} if the TimeDetectorNetworkTimeHelper is being used. */
		public static boolean isInUse() {
		return NetworkTimeHelper.USE_TIME_DETECTOR_IMPL;
		}

		/**
		* An interface exposed for easier testing that the surrounding class uses for interacting with
		* platform services, handlers, etc.
		*/
		interface Environment {

		/**
		* Returns the current elapsed realtime value. The same as calling {@link
		* SystemClock#elapsedRealtime()} but easier to fake in tests.
		*/
		@ElapsedRealtimeLong long elapsedRealtimeMillis();

		/**
		* Returns the latest / best network time available from the time detector service.
		*/
		@Nullable NetworkTimeSuggestion getLatestNetworkTime();

		/**
		* Sets a listener that will receive a callback when the value returned by {@link
		* #getLatestNetworkTime()} has changed.
		*/
		void setNetworkTimeUpdateListener(StateChangeListener stateChangeListener);

		/**
		* Requests asynchronous execution of {@link
		* TimeDetectorNetworkTimeHelper#queryAndInjectNetworkTime}, to execute as soon as possible.
		* The thread used is the same as used by {@link #requestDelayedTimeQueryCallback}.
		* Only one immediate callback can be requested at a time; requesting a new immediate
		* callback will clear any previously requested one.
		*/
		void requestImmediateTimeQueryCallback(TimeDetectorNetworkTimeHelper helper, String reason);

		/**
		* Requests a delayed call to
		* {@link TimeDetectorNetworkTimeHelper#delayedQueryAndInjectNetworkTime()}.
		* The thread used is the same as used by {@link #requestImmediateTimeQueryCallback}.
		* Only one delayed callback can be scheduled at a time; requesting a new delayed callback
		* will clear any previously requested one.
		*/
		void requestDelayedTimeQueryCallback(
		TimeDetectorNetworkTimeHelper helper, @DurationMillisLong long delayMillis);

		/**
		* Clear a delayed time query callback. This has no effect if no delayed callback is
		* currently set.
		*/
		void clearDelayedTimeQueryCallback();
		}

		private static final String TAG = "TDNetworkTimeHelper";
		private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);

		/** The maximum age of a network time signal that will be passed to GNSS. */
		@VisibleForTesting
		static final int MAX_NETWORK_TIME_AGE_MILLIS = 24 * 60 * 60 * 1000;

		/**
		* The maximum time that is allowed to pass before a network time signal should be evaluated to
		* be passed to GNSS when mOnDemandTimeInjection == false.
		*/
		static final int NTP_REFRESH_INTERVAL_MILLIS = MAX_NETWORK_TIME_AGE_MILLIS;

		private final LocalLog mDumpLog = new LocalLog(10, /useLocalTimestamps=/false);

		/** The object the helper uses to interact with other components. */
		@NonNull private final Environment mEnvironment;
		@NonNull private final InjectTimeCallback mInjectTimeCallback;

		/** Set to true if the GNSS engine requested on-demand NTP time injections. */
		@GuardedBy("this")
		private boolean mPeriodicTimeInjectionEnabled;

		/**
		* Set to true when a network time has been injected. Used to ensure that a network time is
		* injected if this object wasn't listening when a network time signal first became available.
		*/
		@GuardedBy("this")
		private boolean mNetworkTimeInjected;

		TimeDetectorNetworkTimeHelper(
		@NonNull Environment environment, @NonNull InjectTimeCallback injectTimeCallback) {
		mInjectTimeCallback = Objects.requireNonNull(injectTimeCallback);
		mEnvironment = Objects.requireNonNull(environment);

		// Start listening for new network time updates immediately.
		mEnvironment.setNetworkTimeUpdateListener(this::onNetworkTimeAvailable);
		}

		@Override
		synchronized void setPeriodicTimeInjectionMode(boolean periodicTimeInjectionEnabled) {
		// Periodic time injection has a complicated history. See b/73893222. When it is true, it
		// doesn't mean ONLY send it periodically.
		//
		// periodicTimeInjectionEnabled == true means the GNSS would like to be told the time
		// periodically in addition to all the other triggers (e.g. network available).

		mPeriodicTimeInjectionEnabled = periodicTimeInjectionEnabled;
		if (!periodicTimeInjectionEnabled) {
		// Cancel any previously scheduled periodic query.
		removePeriodicNetworkTimeQuery();
		}

		// Inject the latest network time in all cases if it is available.
		// Calling queryAndInjectNetworkTime() will cause a time signal to be injected if one is
		// available AND will cause the next periodic query to be scheduled.
		String reason = "setPeriodicTimeInjectionMode(" + periodicTimeInjectionEnabled + ")";
		mEnvironment.requestImmediateTimeQueryCallback(this, reason);
		}

		void onNetworkTimeAvailable() {
		// A new network time could become available at any time. Make sure it is passed to GNSS.
		mEnvironment.requestImmediateTimeQueryCallback(this, "onNetworkTimeAvailable");
		}

		@Override
		void onNetworkAvailable() {
		// In the original NetworkTimeHelper implementation, onNetworkAvailable() would cause an NTP
		// refresh to be made if it had previously been blocked by network issues. This
		// implementation generally relies on components associated with the time detector to
		// monitor the network and call onNetworkTimeAvailable() when a time is available. However,
		// it also checks mNetworkTimeInjected in case this component wasn't listening for
		// onNetworkTimeAvailable() when the last one became available.
		synchronized (this) {
		if (!mNetworkTimeInjected) {
		// Guard against ordering issues: This check should ensure that if a network time
		// became available before this class started listening then the initial network
		// time will still be injected.
		mEnvironment.requestImmediateTimeQueryCallback(this, "onNetworkAvailable");
		}
		}
		}

		@Override
		void demandUtcTimeInjection() {
		mEnvironment.requestImmediateTimeQueryCallback(this, "demandUtcTimeInjection");
		}

		// This method should always be invoked on the mEnvironment thread.
		void delayedQueryAndInjectNetworkTime() {
		queryAndInjectNetworkTime("delayedTimeQueryCallback");
		}

		// This method should always be invoked on the mEnvironment thread.
		synchronized void queryAndInjectNetworkTime(@NonNull String reason) {
		NetworkTimeSuggestion latestNetworkTime = mEnvironment.getLatestNetworkTime();

		maybeInjectNetworkTime(latestNetworkTime, reason);

		// Deschedule (if needed) any previously scheduled periodic query.
		removePeriodicNetworkTimeQuery();

		if (mPeriodicTimeInjectionEnabled) {
		int maxDelayMillis = NTP_REFRESH_INTERVAL_MILLIS;
		String debugMsg = "queryAndInjectNtpTime: Scheduling periodic query"
		+ " reason=" + reason
		+ " latestNetworkTime=" + latestNetworkTime
		+ " maxDelayMillis=" + maxDelayMillis;
		logToDumpLog(debugMsg);

		// GNSS is expecting periodic injections, so schedule the next one.
		mEnvironment.requestDelayedTimeQueryCallback(this, maxDelayMillis);
		}
		}

		private long calculateTimeSignalAgeMillis(
		@Nullable NetworkTimeSuggestion networkTimeSuggestion) {
		if (networkTimeSuggestion == null) {
		return Long.MAX_VALUE;
		}

		long suggestionElapsedRealtimeMillis =
		networkTimeSuggestion.getUnixEpochTime().getElapsedRealtimeMillis();
		long currentElapsedRealtimeMillis = mEnvironment.elapsedRealtimeMillis();
		return currentElapsedRealtimeMillis - suggestionElapsedRealtimeMillis;
		}

		@GuardedBy("this")
		private void maybeInjectNetworkTime(
		@Nullable NetworkTimeSuggestion latestNetworkTime, @NonNull String reason) {
		// Historically, time would only be injected if it was under a certain age. This has been
		// kept in case it is assumed by GNSS implementations.
		if (calculateTimeSignalAgeMillis(latestNetworkTime) > MAX_NETWORK_TIME_AGE_MILLIS) {
		String debugMsg = "maybeInjectNetworkTime: Not injecting latest network time"
		+ " latestNetworkTime=" + latestNetworkTime
		+ " reason=" + reason;
		logToDumpLog(debugMsg);
		return;
		}

		UnixEpochTime unixEpochTime = latestNetworkTime.getUnixEpochTime();
		long unixEpochTimeMillis = unixEpochTime.getUnixEpochTimeMillis();
		long currentTimeMillis = System.currentTimeMillis();
		String debugMsg = "maybeInjectNetworkTime: Injecting latest network time"
		+ " latestNetworkTime=" + latestNetworkTime
		+ " reason=" + reason
		+ " System time offset millis=" + (unixEpochTimeMillis - currentTimeMillis);
		logToDumpLog(debugMsg);

		long timeReferenceMillis = unixEpochTime.getElapsedRealtimeMillis();
		int uncertaintyMillis = latestNetworkTime.getUncertaintyMillis();
		mInjectTimeCallback.injectTime(unixEpochTimeMillis, timeReferenceMillis, uncertaintyMillis);
		mNetworkTimeInjected = true;
		}

		@Override
		void dump(@NonNull PrintWriter pw) {
		pw.println("TimeDetectorNetworkTimeHelper:");

		IndentingPrintWriter ipw = new IndentingPrintWriter(pw, " ");
		ipw.increaseIndent();
		synchronized (this) {
		ipw.println("mPeriodicTimeInjectionEnabled=" + mPeriodicTimeInjectionEnabled);
		}

		ipw.println("Debug log:");
		mDumpLog.dump(ipw);
		}

		private void logToDumpLog(@NonNull String message) {
		mDumpLog.log(message);
		if (DEBUG) {
		Log.d(TAG, message);
		}
		}

		private void removePeriodicNetworkTimeQuery() {
		// De-schedule any previously scheduled refresh. This is idempotent and has no effect if
		// there isn't one.
		mEnvironment.clearDelayedTimeQueryCallback();
		}

		/** The real implementation of {@link Environment} used outside of tests. */
		static class EnvironmentImpl implements Environment {

		/** Used to ensure one scheduled runnable is queued at a time. */
		private final Object mScheduledRunnableToken = new Object();
		/** Used to ensure one immediate runnable is queued at a time. */
		private final Object mImmediateRunnableToken = new Object();
		private final Handler mHandler;
		private final TimeDetectorInternal mTimeDetectorInternal;

		EnvironmentImpl(Looper looper) {
		mHandler = new Handler(looper);
		mTimeDetectorInternal = LocalServices.getService(TimeDetectorInternal.class);
		}

		@Override
		public long elapsedRealtimeMillis() {
		return SystemClock.elapsedRealtime();
		}

		@Override
		public NetworkTimeSuggestion getLatestNetworkTime() {
		return mTimeDetectorInternal.getLatestNetworkSuggestion();
		}

		@Override
		public void setNetworkTimeUpdateListener(StateChangeListener stateChangeListener) {
		mTimeDetectorInternal.addNetworkTimeUpdateListener(stateChangeListener);
		}

		@Override
		public void requestImmediateTimeQueryCallback(TimeDetectorNetworkTimeHelper helper,
		String reason) {
		// Ensure only one immediate callback is scheduled at a time. There's no
		// post(Runnable, Object), so we postDelayed() with a zero wait.
		synchronized (this) {
		mHandler.removeCallbacksAndMessages(mImmediateRunnableToken);
		mHandler.postDelayed(() -> helper.queryAndInjectNetworkTime(reason),
		mImmediateRunnableToken, 0);
		}
		}

		@Override
		public void requestDelayedTimeQueryCallback(TimeDetectorNetworkTimeHelper helper,
		long delayMillis) {
		synchronized (this) {
		clearDelayedTimeQueryCallback();
		mHandler.postDelayed(helper::delayedQueryAndInjectNetworkTime,
		mScheduledRunnableToken, delayMillis);
		}
		}

		@Override
		public synchronized void clearDelayedTimeQueryCallback() {
		mHandler.removeCallbacksAndMessages(mScheduledRunnableToken);
		}
		}
		}

services/core/java/com/android/server/timedetector/EnvironmentImpl.java

+5 −0

Original line number	Diff line number	Diff line
		@@ -129,4 +129,9 @@ final class EnvironmentImpl implements TimeDetectorStrategyImpl.Environment {
		public void dumpDebugLog(@NonNull PrintWriter printWriter) {
		SystemClockTime.dump(printWriter);
		}

		@Override
		public void runAsync(@NonNull Runnable runnable) {
		mHandler.post(runnable);
		}
		}

services/core/java/com/android/server/timedetector/TimeDetectorInternal.java

+19 −1

Original line number	Diff line number	Diff line
		@@ -17,10 +17,13 @@
		package com.android.server.timedetector;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.app.time.TimeCapabilitiesAndConfig;
		import android.app.time.TimeConfiguration;
		import android.app.timedetector.ManualTimeSuggestion;

		import com.android.server.timezonedetector.StateChangeListener;

		/**
		* The internal (in-process) system server API for the time detector service.
		*
		@@ -61,10 +64,25 @@ public interface TimeDetectorInternal {
		/**
		* Suggests a network time to the time detector. The suggestion may not be used by the time
		* detector to set the device's time depending on device configuration and user settings, but
		* can replace previous network suggestions received.
		* can replace previous network suggestions received. See also
		* {@link #addNetworkTimeUpdateListener(StateChangeListener)} and
		* {@link #getLatestNetworkSuggestion()}.
		*/
		void suggestNetworkTime(@NonNull NetworkTimeSuggestion suggestion);

		/**
		* Adds a listener that will be notified when a new network time is available. See {@link
		* #getLatestNetworkSuggestion()}.
		*/
		void addNetworkTimeUpdateListener(
		@NonNull StateChangeListener networkSuggestionUpdateListener);

		/**
		* Returns the latest / best network time received by the time detector.
		*/
		@Nullable
		NetworkTimeSuggestion getLatestNetworkSuggestion();

		/**
		* Suggests a GNSS-derived time to the time detector. The suggestion may not be used by the time
		* detector to set the device's time depending on device configuration and user settings, but

services/core/java/com/android/server/timedetector/TimeDetectorInternalImpl.java

+14 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@ import android.content.Context;
		import android.os.Handler;

		import com.android.server.timezonedetector.CurrentUserIdentityInjector;
		import com.android.server.timezonedetector.StateChangeListener;

		import java.util.Objects;

		@@ -86,6 +87,19 @@ public class TimeDetectorInternalImpl implements TimeDetectorInternal {
		mHandler.post(() -> mTimeDetectorStrategy.suggestNetworkTime(suggestion));
		}

		@Override
		public void addNetworkTimeUpdateListener(
		@NonNull StateChangeListener networkTimeUpdateListener) {
		Objects.requireNonNull(networkTimeUpdateListener);
		mTimeDetectorStrategy.addNetworkTimeUpdateListener(networkTimeUpdateListener);
		}

		@Override
		@NonNull
		public NetworkTimeSuggestion getLatestNetworkSuggestion() {
		return mTimeDetectorStrategy.getLatestNetworkSuggestion();
		}

		@Override
		public void suggestGnssTime(@NonNull GnssTimeSuggestion suggestion) {
		Objects.requireNonNull(suggestion);